please Correct this code

partial class Default2 : System.Web.UI.Page
{

    int i;
    //int count =0;
	string ans= null;
    int[] a=new int[5];
	int t=0;
    SqlDataAdapter  adp= new SqlDataAdapter();
	DataSet ds = new DataSet();
	int ctr = 0;
    
	SqlConnection con = new SqlConnection("Data Source=Sraven\\SQLEXPRESS;Initial Catalog=ObjLogin;Integrated Security=True");
    DateTime mydate = default(DateTime);

	SqlCommand cmd = new SqlCommand();
	DataTable dt = new DataTable();

	DataRow dr = null;
	public void Show()
	{

        
        Session["Answered"] = dt;
		View v = this.View1;


		Label l = default(Label);
		l = (Label)v.FindControl("Label1");
        l.Text = dt.Rows[ctr]["Serial"] + ",";
		l = (Label)v.FindControl("Label2");
        dt.Rows[ctr]["question"] = l.Text; 

        //dt.Rows[ColumnName/ID][RowID] 
        

		RadioButtonList r = default(RadioButtonList);
		r = (RadioButtonList)v.FindControl("RadioButtonList1");
		r.Items.Clear();

        r.Items.Add(dt.Rows[ctr]["choice1"].ToString());
       r.Items.Add(dt.Rows[ctr]["choice1"].ToString());
       r.Items.Add(dt.Rows[ctr]["choice1"].ToString());
       r.Items.Add(dt.Rows[ctr]["choice3"].ToString());
       r.Items.Add(dt.Rows[ctr]["choice4"].ToString());
       dt.Rows[ctr]["selected"]=r.SelectedIndex;

        



		Session["ctr"] = ctr;
	}

    protected void Timer1_Tick1(object sender, EventArgs e)
    {
        //DateTime mydate = default(DateTime);
        DateTime mydate2 = DateTime.Now;
        DateTime mydate3 = default(DateTime);

        try
        {
            //TimeSpan DateDiff = DateTime.Parse(dr["IntervalEnd"].ToString()).Subtract(DateTime.Now);

            //TimeSpan DateDiff = DateTime.Parse(mydate.Subtract(mydate2));
            //mydate3 = mydate.Subtract(mydate2);
            mydate3 = DateTime.Parse(mydate.Subtract(mydate2).ToString());
            this.Label5.Text = "Time Left: " + mydate3.ToShortTimeString();
        }
        catch (Exception ex)
        {
            this.Label5.Text = "Error Setting up the Timer. Contact Admin";
        }


        if (mydate3.ToShortTimeString() == "00:00:00")
        {
            int marks = 0;
            Session["Answered"] = dt;

            foreach (DataRow  x in dt.Rows)
            {
                
                if (Convert.ToInt32(x["Selected"].ToString()) + 1 == Convert.ToInt32(x["correct"].ToString()))
                {
                    marks += 1;

                }
            }
            Response.Redirect("default3.aspx?marks=" + marks);

        }

        }

    protected void Page_Load(object sender, System.EventArgs e)
    {
        mydate = DateTime.Parse(Request.Cookies["start"].Value);
       



        if (!IsPostBack)
        {
            this.MultiView1.ActiveViewIndex = 0;
            con.Open();
            cmd.Connection = con;

            //Random arbit = new Random();
            ////VBMath.Randomize();
            
            Random randomNumber = new Random();
            randomNumber.Next();

        X:
            

            for (i = 0; i <= a.GetUpperBound(0); i++)
            {
                t = randomNumber.Next();

                

                if (Array.IndexOf(a, t) == -1)
                {
                    a[i] = t;

                }
                else
                {
                    goto X;
                }

            }